Donald Trump has insisted that he is not taking talk of impeachment seriously as he once again claimed he had done nothing wrong in a phone call with the president of Ukraine.Arriving at the United Nations in New York for a session on religious freedom, Mr Trump said the row over his “perfect” phone call with Volodymyr Zelensky was a “Democrat witch-hunt”, adding: “They failed with Russia, they failed with recession, they failed with everything, and now they’re bringing this up.” Meanwhile, his personal lawyer, the former New York mayor Rudy Giuliani, told Fox Business he could not be “100 per cent sure” the president didn’t threaten to cut off aid to Ukraine unless the former Soviet country agreed to investigate Joe Biden’s son.